1. Field of the Invention
This invention relates to a device for coupling and locking a bracket, which is provided with a buckle of a seat belt, in case of danger to a retaining member, which is fixed in a vehicle.
2. Description of the Prior Art
For increased riding convenience it may be desirable to connect the bracket which is provided with the buckle of a seat belt to the seat frame plate or to a side plate of the seat so that the person who is to be held on the seat will find the buckle always at the same location when he or she desires to insert the latch striker into the buckle, regardless of the elevation and longitudinal position to which the seat has been adjusted.
If the safety belt is provided with the belt tightener which has been described in the patent application which is entitled "Belt Tightener for Seat Belts in Vehicles" and is filed on even date herewith, so that the safety is the occupant is improved, the bracket which carries the buckle is guided for a longitudinal displacement in a housing, which is connected to the sheet metal frame of the seat or to another part of the vehicle and said housing is provided with means which permit a pull-in movement of the bracket and block its movement in the opposite direction. But, as a rule, seat frame plates, seat side plates, housing for locking the bracket that is provided with the buckle, and other parts for mounting the bracket cannot be sufficiently stiff and strong unless considerable costs are incurred, which add to the costs of the vehicle. These parts should be so stiff and strong that in case of a crash or other accident they will reliably take up and transmit the tensile forces then acting on the seat belt. For this reason it is a desire to provide an device which is of the kind described first hereinbefore and which relieves the intermediate structures and housings for holding the bracket for the buckle and which in case of danger directly couples the bracket to a retaining member, which is fixed in the vehicle.
In a device of the kind described first hereinbefore and known from Published German Application No. 28 00 261, a tensile lug which carries the buckle is connected by a shearable rivet to a wall of a guide housing, which is approximately rectangular in cross-section. The guide housing is secured by spacers to a fixture element or to the frame of the seat. A toothed lug, which at its lower end is adapted to be anchored to the seat rail, is so guided on the inside surface of the guide housing that is opposite to the tensile lug that the toothed lug will be displaced relative to the guide housing during an adjustment of the seat in height. The tensile lug which carries the buckle is formed on its lower portion with two locking teeth, which fit in between the teeth of the toothed lug. If the accelerating forces which are due to a crash or other accident cause the wearer of the seat belt to pull out the tensile lug by means of the buckle, the rivet which connects the tensile lug to the guide housing will be sheared off so that inclined slide faces will guide the lower portion of the tensile lug toward the toothed lug, the locking teeth of the tensile lug will interengage with the teeth of the toothed lug, and the tensile lug will thus be anchored to the toothed lug that is connected to the seat rail.
Even a sharp braking and/or smaller accidents usually give rise to substantial accelerating forces on the wearer of the seat belt and whereas said forces are weaker than those which are exerted in case of a crash they will result in a considerable load on and stressing of the seat and for this reason should also directly be transmitted to the body of the vehicle.